Numerical Study of Free Convection Heat Transfer in a Square Cavity with a Fin Attached to Its Cold Wall

2011 ◽  
Vol 42 (3) ◽  
pp. 251-266 ◽  
Author(s):  
Saeid Jani ◽  
Meysam Amini ◽  
Mostafa Mahmoodi
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Cold Wall ◽  
Convection Heat ◽  
Square Cavity ◽  
Free Convection Heat

scholarly journals Numerical study on laminar free convection heat transfer between sphere particle and high pressure water in pseudo-critical zone

2014 ◽  
Vol 18 (4) ◽  
pp. 1293-1303 ◽  
Author(s):  
Liping Wei ◽  
Youjun Lu ◽  
Jinjia Wei
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Free Convection ◽  
Fluidized Bed ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Boussinesq Approximation ◽  
Convection Heat ◽  
Pressure Water ◽  
Free Convection Heat

Supercritical water fluidized bed reactor (SCWFBR) is a promising new reaction vessel which can effectively gasify wet biomass and efficiently produce hydrogen. Free convection heat transfer from particle in supercritical water (SCW) is a major basic heat transfer mechanism in a fixed bed or fluidized bed with low superficial velocity. In this paper, numerical study on the steady free convection heat transfer around single sphere particle in high pressure water of pseudo-critical zone was carried out. Both the Boussinesq approximation method and real properties model (considering variable specific heat, density, viscosity, and conductivity of SCW) were incorporated to simulate the flow and temperature field. With respect to Boussinesq approximation, real properties model shows higher vorticity and temperature gradients in the vicinity of the sphere surface, which shows variation of thermo-physical property has remarkable effect on the free convection heat transfer process. High local Nusselt number and high heat transfer rate were observed with real properties model.

scholarly journals Free Convection Heat Transfer from Horizontal Cylinders

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 559
Author(s):  
Janusz T. Cieśliński ◽  
Slawomir Smolen ◽  
Dorota Sawicka
Keyword(s):  
Heat Transfer ◽  
Rayleigh Number ◽  
Free Convection ◽  
Convection Heat Transfer ◽  
Horizontal Tube ◽  
Correlation Equations ◽  
Convection Heat ◽  
Number Range ◽  
Heated Cylinder ◽  
Free Convection Heat

The results of experimental investigation of free convection heat transfer in a rectangular container are presented. The ability of the commonly accepted correlation equations to reproduce present experimental data was tested as well. It was assumed that the examined geometry fulfils the requirement of no-interaction between heated cylinder and bounded surfaces. In order to check this assumption recently published correlation equations that jointly describe the dependence of the average Nusselt number on Rayleigh number and confinement ratios were examined. As a heat source served electrically heated horizontal tube immersed in an ambient fluid. Experiments were performed with pure ethylene glycol (EG), distilled water (W), and a mixture of EG and water at 50%/50% by volume. A set of empirical correlation equations for the prediction of Nu numbers for Rayleigh number range 3.6 × 104 < Ra < 9.2 × 105 or 3.6 × 105 < Raq < 14.8 × 106 and Pr number range 4.5 ≤ Pr ≤ 160 has been developed. The proposed correlation equations are based on two characteristic lengths, i.e., cylinder diameter and boundary layer length.

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